const path = require('path')

const webpack = require('webpack')

const { VueLoaderPlugin } = require('vue-loader')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')

module.exports = {
  entry: {
    app: './src/main.js'
  },

  output: {
    filename: 'js/[name].[hash:8].js',
    path: path.resolve(__dirname, 'dist'),
    chunkFilename: 'js/[id].[contenthash:8].js'
  },

  module: {
    rules: [
      // 加载 vue
      {
        test: /\.vue$/,
        use: 'vue-loader'
      },
      // 加载 less css
      {
        test: /\.(less|css)$/,
        use: [
          {
            loader: MiniCssExtractPlugin.loader,
            options: {
              publicPath: '../',
              // 开发环境开启热重载
              hmr: process.env.NODE_ENV === 'development'
            }
          },
          'css-loader',
          'less-loader'
        ]
      },
      // 加载 js
      {
        test: /\.js$/,
        exclude: /node_module/,
        use: [
          {
            loader: 'babel-loader',
            options: {
              presets: ['@babel/preset-env']
            }
          },
          {
            loader: 'eslint-loader',
            options: {
              // 发生错误时终止打包
              failOnError: true
            }
          }
        ]
      },
      // 加载 images
      {
        test: /\.(png|jpe?g|gif|svg)$/i,
        use: {
          loader: 'file-loader',
          options: {
            esModule: false,
            outputPath: 'images/'
          }
        }
      },
      // 加载 fonts
      {
        test: /\.(ttf|woff|woff2|eot|otf)$/,
        use: {
          loader: 'file-loader',
          options: {
            esModule: false,
            outputPath: 'fonts/'
          }
        }
      }
    ]
  },

  plugins: [
    // 加载 vue 单文件所需
    new VueLoaderPlugin(),

    // 创建 index.html，自动引入模块
    new HtmlWebpackPlugin({
      title: 'My App',
      template: './public/index.html'
    }),

    // 定义全局变量
    new webpack.DefinePlugin({
      BASE_URL: JSON.stringify('')
    }),

    new MiniCssExtractPlugin({
      filename: 'css/[name].[contenthash:8].css',
      chunkFilename: 'css/[id].[contenthash:8].css'
    })
  ]
}
